Since there are no families yet, I've been making all of my enemies out of a single object. It's working well so far, but being unable to deactivate the platform behavior for non-platform enemies is causing some trouble.
Also, there was talk of a "jump-through platform" behavior a little while ago. Any idea if that will make it into the next build? I've made my own jump-through platforms by deactivating/activating solids depending on the player's position, but this won't work with platform enemies.